Engine brake



Ma l, 1935. B. UCKO 2,002,196

ENGINE BRAKE Filed March 9, 1931 INVENTOR flernard Mk0,

a if: cmMQ m 111,5 ATTORNEYS Patented May 21, 1935 v ma 1 was;

. to International Motor Company, New York, '1 N. 1.,dcorporationo!Delaware appumidn Marcus; 1981, serial so. and

' sfoi misucilizaeoi I The'present invention relates toiengine bralre'sand embodies, more specifically, an improved form of brake, wherein theengine is converted i into a true two cycle aircompressor, thus effec-'l tively braking the same.

More particularly, the invention embodies an improved braking mechanismfor internal combustion engines which is readily applicable to standardmakes and types of engines without 'modifying the construction thereofor altering,

arm shaft turning mechanismiin such fashion as to cause the exhaustvalve opening mechanism to function when the rocker arm valve actuatingmechanism is rendered inoperative, thus causing air tobe drawn into the'cylinders upon thedown strokes of the respective pistons and compressedupon the upstrokesp An object of the invention is to provide'an enginebrake design which does not add to the length oftheengine. I i

A further object of theinvention is toprovide an engine brake design"which is simple in construction andoperationand theparts of which maybe added to any engine structure without modifying the engine design ormaterially altering the auxiliary elements thereof. I A further objector the invention is to-provide a device of the above character, whereinthe conventional valve mechanism is utilized as the engine brakemechanism when it is desired'that the engine operate as abrake. p j i ii A further object of the invention is to provide a rigid andquietdrive, this object being attained by the utilizing of mechanism whichdoes not require the shifting of the cam shaft, 9. further obiect oi theinvention being toprovide a'structure wherein the brake elements areindependent of the engine and thus do not impair thenormal operation ofthe engine upon failure of such elements.' Further objects, notspecifically enumerated above, will be apparentas the invention isdescribed in greaterdetaii in connection with the accompanying drawing,wherein the single figure of the drawing isa view in section takenthrough acylinder head andvalve actuating mechanism of aistandard formof engine,the engine brake" structure of the present invention beingshown as pads 290i therespective rods 25.

brakes 'I'heoperation of the deviceis as folhaustpassage H and anexhaust port l2. E x- B haust valve I3 is mounted upon a valve stem it iI which'is carried in a sleeve l5 mounted in, the head and a collar 16seats a valve spring- H to maintain the valve normallyclosed, U

Rocker arm shaft 18 is mounted upon eccenl9 trics l9. and is thusshifted eccentrically of the axis of the eccentricsby means of ashifting lever 20. Rocker armsiil are carried by, the shaft I 8 and areiormed with heads 22 which engage the top ofvalve stems UL; i Upon theother end oi therockermarms, adjust able tappets 23 are mounted, thesetappets being engaged bycupsid upon push rods 25; Lost motion springsare provided between the rocker arms and the respective push rods. 25,and inlet 20 and exhaust earns 21 on cam shaft 28 engagethe Theforegoing mechanism is of standard form and typical of internalcombustion engines. In combination with valve actuating mechanisms of 25this character, a brake actuating mechanism is provided which includes aconduit 30 communicating with the main oil line, not shown. Upon a powershaft which may be the cam shaft or drivenby the cam shaft, a brake cam3| is pro- 30 vided; this cam being a double lobe cam for each cylinder.The cam actuates. a primary brake ac- .tuatine pump 33 whichcommunicates with a conduit 34. It will be understood, of course, thatwcationbetween theconduit 34 and: the conduit 3 30, while a reieasevalve 41 and conduit "permits the oil pumped by the pump to be returnedto the engine when the brake mechanism is notinuse.

A suitable link 43 causes the release valve I to cooperatedsimultaneously with therocker am shaft shifting lever to preventlubricant ;frcm being returned to the engine-lubricating system when itis desired to operate the engine actuate the inlet and exhaust valves inthe usual manner. When it is no longer desired to actuate the engine,the rocker arm shaft is shifted by meansof the lever 20 to lift therocker arms and raise the tops 23 from the sockets 24, thusrenderingthepush rods ineffective to actuate the valve mechanism. Boththe inlet and exhaust valves of the engine therefore remain closed andthe braking mechanism functions to lift the exhaust valves upon the downstrokes'of the pistons to conduit. 34 and forces the piston 36downwardly to depress shaft 38, head 22, and valve'rod l4.

This takes place on each exhaust valve as the respective pistons movedownwardly and the engineisthus converted into an air compressor.

It will be seen that theforegoing mechanism does not add to the lengthof the engine and utilizes the conventional valve mechanism of theengine to cause the engine to function as an air compressor and thuseffect braking. Noshifting cam shaft is required therefore providing arigid and noiseless drive and the parts are relatively inexpensive andsimple to construct and to maintain. The engine design is not modifiednor is the auxiliary equipment thereof materially changed and thebraking mechanism does not constitute a part of the'engine whichfunctions during nor mal engine operation. In view of this lastcondition, failure of the brake system does not impair'the normaloperation of the engine.

Where a multi-cylinder engine is formed of a plurality of independentblocks each carrying one or more cylinders, it willbe seen thatthe valvemechanism of the cylinders of the respective blocks may be utilizedingroups or simultaneously, to effect the progressive graduation of thebraking effect.

It is of considerable advantage to provide a bleed valve 44 at thehighest point in the fluid system, the valve being operated by stem 45and cam 46 on the rocker arm shaft l8. When the rocker arm shaft isshifted to such position that the engine functions as a brake, the bleedvalve 44 is closed under the action of spring 41 and the fluid system isthus rendered tight. Upon the return of the rocker arm shaft to itsnormal position the cam 46 opens the valve MS, as will be readilyapparent from an inspection of the drawing.-

' While the invention has been described with specific reference to theaccompanying drawing, it is not to be limited, save as deflned in theappended claims.

I claim as my invention: l

1. In combination with an engine having an exhaust valve and a rockerarm for actuating the valve, means to vary the position of the rockerarm to render it ineffective to actuate the valve, a pump, a motoractuated by the pump, and means to cause the motor to open the exhaustvalve. j

I 2. In combination with an engine having an exhaust valve, a rocker armfor actuating the valve, and a cam shaft for actuating the arm, means tovary the position of the axis 01. the arm to render it ineffective toactuate the valve, a pump driven by the cam shaft, a motor actus m lows.Under normal running conditions, the rocker arm shaft is inthe downposition as shownin-solid lines in the drawing and the push rods ated bythe pump, and means actuated by the motor to open the valve.

3. In combination with an engine having an exhaust valve, a piston, arocker arm for actuating the valve, and a cam shaft for actuating thevarm, means to vary the position of the axis of exhaust valve, a rockerarm for actuating the valve, and sham shaft for actuating the arm,

means to vary the position of the axis of the arm to render itineffective to actuate the valve, a pumpdriven by the cam shaft, amotor, a conduit connecting the pump and motor, a valve for relievingpressure in the conduit, a conduit communicating with a source of fluid,and a check valve in the last named conduit to prevent the fiowof fluidfrom the pump and. motor to the source. p

5. In combination with an engine having an exhaust valve, a rocker armfor actuating the valve, and a cam shaft for actuating the arm, means tovary the position of the axis of the arm to render itineffective toactuatethe valve, a pump driven by the cam shaft, a motor, a conduitconnecting the pump and motor, a valve for relieving pressure in theconduit, a conduit com-r municating with a source of fluid, a checkvalve in the last named conduit toprevent the flow of fluid from thepump and motor to the source, and means to actuate the relief valve fromthe rocker arm actuating means.

6. In combination with an engine having an exhaust valve, a rocker armfor actuating the valve, and a cam shaft for actuating the arm, means tovary the position of the axis of the arm to render it ineffective toactuate the valve, a pump driven by the cam shaft, a motor actuated bythe pump having a piston rod adapted to engage the rocker arm, meansto'mount the motor above the valve stem, a conduit connecting the pumpand motor, a valve for relieving pressure in the conduit, a conduitcommunicating with a source of fluid, and a check valve in the lastnamed conduit to prevent the flow of fluid from the pump and motor tothe source.

7. In combination with an engine having an exhaust valve, a rocker armfor actuating the valve, and a cam shaft for actuating the arm, means tovary the position of the axis of the arm to render it ineffective toactuate the valve, a pump driven by the cam shaft, a motor actuated bythe pump having a piston rod adapted to engage the rocker arm, means tomount the motor above the valve stem, a conduit connecting the pump andmotor, a valve for relieving pressure in the conduit, a conduitcommunicating with a source of fluid, a check valve in the last namedconduit to prevent the flow of fluid from the pump and motor to thesource, and means to actuate the relief valve from the rocker armactuating means.

8. A valve mechanism for internal combustion engines permitting theengine to act as a braking means, comprising the usualvalve-operating'assembly including a push rod element and a connectinglever element between the push rod and said elements of each assemblyfor rendering the said exhaust-valve operating assembly inoperative andmeans for opening each of the said exhaust valves during the down strokeof the engine piston. V

9. A valve mechanism for internal combustion engines permitting theengine to act as a braking means, comprising the usual valve-operatingassembly including a push rod and a connecting lever element between thepush rod and the exlever element of each assembly for displacing saidlever element to render the said exhaustvalve operating assemblyinoperative and means for positively opening the said exhaust valve'haust valve stem for positively opening each exhaust valve, meansoperating on the connecting

